SOUTH BURLINGTON — Passengers flying out of Vermont’s largest airport were down in October by more than 10 percent from the same month a year earlier.

That’s according to statistics released by Burlington International Airport, which says 54,916 people boarded planes there in October. That was down from 61,092 in October of 2011.

Outgoing traffic was up slightly for the first five months of this year over the same period of 2011, but has been down in June, July, August, September and October. October saw the biggest drop over the same month a year earlier.

The number of passengers flying out of Burlington has been in decline since peaking at more than 708,000 in 2009, with about 648,000 boarding planes at the airport last year.